Help - Save Games?

My brother got his new computer with Vista on it. I'm still getting
comfortable with Vista. He has his own user of course, which was the one
created first, then I made my own user. I made sure to make myself an
aministrator. If you look at our log in screens you will see TWO
administrators... Him and me.

No problems with Vista so far. However, I installed a game on my user for
the first time... "Black and White." I'm a person who saves often and keeps
many save files. I noticed everytime I saved in B&W, the save game sort of
vanished... I couldn't load a game. I thought this was a problem with B&W,
but I realize now, that Vista is probably not letting black and white save
any files to the hard disc. How do I fix this? On my brothers login I KNOW
he can save games (Unless he plays them all without saving... I see him
playing offline games all the time). Is there a setting I can change or am I
forced to play black and white on my brother's user?

Haven't tried it on other games yet, but I'm going to install the sims and
find out if I have the same problem there.